Custom callusing is a big part of the business at Northwest Vinifera, a Washington State grape nursery.

Markus Freepons of Northwest Vinifera, showed his grape callusing pits during a field day held last August sponsored by the Washington Association of Wine Grape Growers.

Photo by Melissa Hansen

Marcus Freepons, owner of the grape nursery Northwest Vinifera, says his business is about making a lot out of a little.

He’s a farmer first, growing cherries and Concord juice grapes in Grandview, Washington, but his grape nursery has grown into a significant business. This year, between his custom callusing services and potted greenhouse vines and field-grown plants, he will handle about 1.2 million cuttings.

The custom callusing service he provides for growers now makes up a majority of his business. In perfecting his callus technique, Freepons has learned the right combination of warm temperatures, moisture, and rooting hormones to consistently encourage rooting or callusing on the basal ends of dormant wood supplied by growers. Freepons likens callus, the white tissue that forms on cut surfaces of the dormant cutting, to a Cheerio or rice kernel. Callusing is done to promote root growth and improve success rates when planting.

Years ago, growers who wanted to expand plantings from their own vines would place sticks of dormant cuttings in pits dug in the ground, covered with dirt and black plastic to draw in heat to form calluses on the wood. The pits were at the mercy of weather and results were often variable.

By controlling temperature and moisture, Freepons has developed a formula for callusing that yields uniform and consistent results. He uses apple bins filled with clean mortar (sand) for the “pit.” Heat coils are placed on top of the sand to warm up the basal end and encourage quicker rooting. Sets of bins are housed inside greenhouses to maintain consistent temperatures.

His custom service begins with dormant wood brought to Northwest Vinifera by growers who want to serve as their own nursery. Wood is cut into sticks about 14 inches long and placed upside down in the sand with the basal end on top. Temperature and moisture are monitored twice a day. After about ten days in this regulated environment, callusing has usually begun.

“Once we see little Cheerios of callus, we begin coordinating with the grower for delivery,” Freepons said. Bins are packed with burlap and the grower picks up the callused sticks for field or greenhouse planting. “We can get our timing down for the grower to within one to two days.”

With three greenhouses, each containing 20 sets of callus bins, he can have up to about 750,000 sticks in callus media at one time. Each callus bin set (two apple bins) contains some 14,000 sticks. During peak nursery season, Freepons employs about 35 workers, a team that can process about 70,000 sticks per day.

“The key to making a lot out of a little is a dedicated and skilled team,” he said.

Grandview grape and cherry grower Dick Boushey said that he used to do much of his own callusing. “But lately, I’ve been contracting the service with Marcus, because I get so much more consistency and uniformity, and the end results are so much better,” he said. “All of the wood is at the same stage. When I did it on my own, sticks were at all stages, and some didn’t make it.”

Freepons stressed that growers using their own wood for planting should test the vines for diseases and viruses. Although none of the plant material he sells is certified, all of the plant material that he sources comes from virus-tested vineyards.

Early years

Freepons got into the grape nursery business in the late 1990s after he was asked by a major winery in the state if he could help expand the cuttings from one of their mother blocks that they wanted to use for vineyard expansion. He soon began working with potted vines grown under the greenhouse to shorten the propagation time involved with growing a vine ready for planting. From the bulk, dormant wood collected from about 75 plants, Freepons was able to grow 7,000 potted vines under the greenhouse.

“The potted vines take a lot of labor, and growers must be careful in handling and planting,” he said. Though potted vines still make up a good portion of his nursery business, the custom callusing is the area that has really taken off.

Freepons said that his grower list is a “short” one, but he is open to expanding his business. “I’m a commercial nursery, although I operate under the radar and don’t have a Web site like most do.”

He charges 35 cents per stick for custom callusing; $1.75 for a two-bud potted vine or regular greenhouse plant; and $1.65 for field-run plants.